| # | Time | Username | Problem | Language | Result | Execution time | Memory |
|---|---|---|---|---|---|---|---|
| 1147808 | thunopro | COVID tests (CEOI24_covid) | C++20 | 0 ms | 0 KiB |
#include<bits/stdc++.h>
using namespace std ;
#define maxn 200009
#define ll long long
#define pb push_back
#define fi first
#define se second
#define left id<<1
#define right id<<1|1
#define re exit(0);
#define _lower(x) lower_bound(v.begin(),v.end(),x)-v.begin()+1
#define TIME ( 1.0*clock() / CLOCKS_PER_SEC )
const int mod = 1e9+7 ;
const int INF = 1e9 ;
typedef vector<int> vi ;
typedef pair<int,int> pii ;
typedef vector<pii> vii ;
template < typename T > void chkmin ( T &a , T b ) { if ( a > b ) a = b ; }
template < typename T > void chkmax ( T &a , T b ) { if ( a < b ) a = b ; }
void add ( int &a , int b )
{
a += b ;
if ( a >= mod ) a -= mod ;
if ( a < 0 ) a += mod ;
}
void rf ()
{
freopen ("bai1.inp","r",stdin) ;
}
mt19937 rng (0) ;
int _pow ( int a , int n )
{
if ( n == 0 ) return 1 ;
int res = _pow (a,n/2) ;
if ( n % 2 ) return 1ll*res*res%mod*a%mod ;
else return 1ll*res*res%mod ;
}
int n , test ;
double p ;
bool a [maxn] ;
bool test_students ( vector<bool> mask ) ;
vector<bool> find_positive () ;
int main ()
{
ios_base::sync_with_stdio(0);
cin.tie(0);cout.tie(0);
// rf () ;
cin >> n >> p >> test ;
for ( int i = 0 ; i < n ; i ++ ) cin >> a [i] ;
while ( test -- )
{
vector<bool> positive = find_positive () ;
cout << "A " ; for ( auto x : positive ) cout << x ; cout << endl ; re
char result ; cin >> result ;
if ( result == 'W' ) return 0 ;
}
}
//#define LOCAL
//
//#ifdef LOCAL
//bool test_students ( vector<bool> mask )
//{
// bool has = 0 ;
// for ( int i = 0 ; i < n ; i ++ ) if ( mask [i] == 1 ) has |= a [i] ;
// return has ;
//}
//#endif
//
//#ifndef LOCAL
//bool test_students ( vector<bool> mask )
//{
// cout << "Q " ; for ( auto x : mask ) cout << x ; cout << endl ;
// bool res ; cin >> res ; return res ;
//}
//#endif
bool query ( int l , int r , vector<int> can_covid )
{
vector<bool> students (n,0) ;
for ( int i = l-1 ; i <= r-1 ; i ++ ) students [can_covid[i]] = 1 ;
return test_students (students) ;
}
vector<bool> find_positive ()
{
vector<bool> positive (n,0) ;
while ( true )
{
vector<int> can_covid ;
for ( int i = 0 ; i < n ; i ++ ) if ( positive [i] == 0 ) can_covid . push_back (i) ;
if ( !query (1,can_covid.size(),can_covid) ) break ;
int l = 1 , r = can_covid.size () ;
while ( l <= r )
{
if ( l == r )
{
positive [can_covid[l-1]] = 1 ;
break ;
}
int mid = (l+r)/2 ;
if ( query (l,mid,can_covid)) r = mid ;
else l = mid + 1 ;
}
}
return positive ;
}